docs: def datetime(self):
          """Conversion of the Date object into a ``datetime.datetime``
  
          The resulting object is a timezone-naive instance with the same scale
          as the originating Date object.
          """
          if 'dt_scale' not in self._cache.keys():
              self._cache['dt_scale'] = self._datetime - timedelta(seconds=self._offset)
          return self._cache['dt_scale']